Bats sleep 18-20 hours per day.
5
Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240
One reason that kittens sleep so much is because a growth hormone is released only during sleep.
212
Studies show that the colder the room you sleep in, the more likely you are to have a bad dream.
28
Some people have a "natural alarm clock" allowing them to wake up when they want. This is actually caused by a burst of the stress hormone adrenocorticotropin.
15
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
47% of people have a nightmare at least once a month.
186